Analysis of Energy Performance and Green Strategies in the Foreign High-Performance Buildings

1.1. Background and Purpose

International environmental treaty against global warming has continuously developed with awareness that compromise of economic development and environmental conservation directly lead to the progress of future society. All over the world, need for sustainable development is gaining its importance. So paradigm of national development intending to protect environmental pollution and greenhouse gas has been proposed, and every country is presenting many systems and policies for greenhouse reduction.

Especially, energy consumption in building takes up approximately 25% of the whole nation consumption and with the improvement in lifestyle and increase in number of buildings, energy consumption increase is expected. According to this, Korea has announced 'Low Carbon Green Growth' aiming at 30% reduction compared to BAU(Business As Usual) until 2020 as a new national vision. Efforts to establish energy efficiency strategy in building energy are sustained currently, and establishment of systematic regulations such as revising 'Building Energy Conservation Design Standards' is being done.

But we need the follow-up countermeasure for ‘high-performance building’ based on these systematic regulations. Now, United States and European communities have developed high-efficiency technology for the efficiency of building energy. Korea is attempting to certify green buildings through application of green building strategy but the situation is still insufficient to catch up the level of foreign high technology which is being developed rapidly.

Thus this research intends to comprehend the technological trend applied to each building by analyzing energy performance level through case study analysis in the foreign high-performance building.

1.2. Research method and scope

The flow chart of this research for realization of high-performance building is shown in Fig. 1. In this study, high-performance building should be the ones that have been built in recent 10 years and was limited only to those with LEED certification in United States, with CASBEE certification in Japan, with Passive House certification in Germany. We analyzed annual energy consumption of each selected building and compared these to three standards of domestic and foreign energy performance.

Fig. 1.

Flow diagram

1. CBECS(Commercial Buildings Energy Consumption Survey) was used. This energy standard is a national sample survey that collects energy usage data and building features related to energy in United States which having been performed since 1979 until now.

2. To compare annual energy consumption in recent 10 years, we compared annual energy consumption of high-performance building that requires minimum demand condition of ASHRAE 90.1 Standard 2004(Office Building).

3. We compared annual energy consumption of high-performance building to building energy efficiency rating standard (1st grade) in Korea.

Technology applied to foreign high-performance buildings was classified into four kinds, such as Envelope Improvement, HVAC System & Control, Renewable Energy, and Indoor Environment Control.

2.1. Literature Review

Researches related to high-performance building have mainly been focusing on certification system analysis such as LEED and CASBEE. In domestic case Park, Seoung-Tae and Kim, Kang-Soo¹⁾ (2009) analyzed the cases of LEED after classifying buildings into office, education, living and culture to examine the international trend of eco-friendly building and examined technology applied in certified building cases.

In foreign cases, Edwin Rodriguez-Ubinas²⁾ and others (2014) analyzed energy efficiency and technology strategy of passive house building. Analyzed technology includes thermal performance, ice thermal storage, evaporative cooling and night ventilation strategy, and we examined the effect of these technologies on energy performance and comfort in passive house.

Domestic researches that analyzed high-performance building have continuously been performed, but still detailed analysis regarding energy performance and application technology are insufficient and mainly focusing on general analysis.

Thus this research intends to quantitatively comprehend the technology trend applied to each building and analyze energy performance level through case analysis in the foreign high-performance buildings.

3.1. Selection of foreign high-performance building

List of foreign high-performance buildings is shown in Table 1 and they were selected according to following conditions.

• Buildings that have been built within recent 10 years
• Buildings with the certification of LEED(Platinum~Silver), Passive house certification, CASBEE ‘S’ class
• Buildings with simulation energy usage record using program validated by DOE or actual energy usage data.

Table 1.

Foreign high-performance building list(U.S.A, Germany=GER, Japan=JPN Total : 20)

Fig. 2.

Database map of foreign high-performance buildings

Based on this, 12 in United States, 4 in Germany and 4 in Japan, and 20 in total were shown in Table 1 and the database map reviewed is shown in Fig. 2.

General information and comparison between annual energy consumption and its reduction rate of foreign high-performance building are shown in Table 2. Table 2 summarized building name, certification class, building location & climate, usage, years built, area, energy consumption and reduction rate. Regarding energy consumption, those of buildings with more than one data or all simulation energy usage along with actual energy consumption are belong to the case of United States and Germany. Actual energy consumption data are collected in the case of Japan.

Annual energy consumption was classified into 5 levels that are below 100kWh/m².a, 100~150kWh/m².a, 150~200kWh/m².a, 200~ 250kWh/m².a, 250~300kWh/m².a, 300~350kWh/m².a and more than 350kWh/m².a. Annual energy consumption of total 20 high-performance buildings in United States, Germany and Japan was examined and organized in order from lowest to highest by each level. Besides, regarding energy reduction rate, 146.6 kWh/m².a that is the upper limit of annual energy consumption of office building satisfying the minimum requirements of ASHRAE 90.1 2004 and 200~260 kWh/m².a that is the requirement for 1st grade of Korea building energy efficiency rating system are selected for comparison.

Buildings with annual energy consumption below 100kWh/m².a were no. 1(Wind NRG Partners Manufacturing Facility), 2(Solarsiedlung GmbH), 3(Energon Office Building), 4(City of White Rock Operations Building), 5(Supfina Grieshber GmbH & Co.), 6(Lu-Teco Office Building), and 7(Alberici Corporate Headquarters) of United States and annual energy consumption reduction rate was 33.2%~67.3% compared to 146.6 kWh/m².a, annual energy consumption of office building that satisfies the minimal requirements of ASHRAE 90.1 2004. Compared to the upper limit between 200~260 kWh/m².a which is the guideline for 1st grade of Korea building energy efficiency rating it was analyzed that annual energy consumption was reduced by 62.3%~81.5%.

Buildings consumed annual energy from 100kWh/m².a to 150kWh/m².a were no. 8(Chicago Center for Green Technology), 9(Heifer International Headquarters), 10(Environmental Protection's Cambria Office), 11(CBF Merrill Environmental Center), and 12(Electronic Arts Headquarters Phase II), and showed reduction rate each by 29.1%, 27.7%, 20.9%, 17.5%, and 7.9% compared to the minimum requirements of ASHRAE 90.1 2004. Compared to the guideline for 1st grade of domestic building energy efficiency rating, it showed energy reduction by 48.1%~60.0%.

Buildings that showed annual energy consumption of 150~200kWh/m².a much more than minimum requirements of ASHRAE 90.1 2004 were no. 13(Center for Neighborhood Technology). Annual energy consumption range of 200~ 250kWh/m².a were no. 14(The Conde Nast Building at 4Times Squre) and 15(The Plaza at PPL C enter). But they used energy reduced each by 30.8%, 22.7%, 15.8% in its annual energy consumption rather than 260 kWh/m².a which is the standard upper limit for 1st grade of domestic building energy efficiency rating. Buildings distributed in 250~300kWh/m².a that is higher than annual energy consumption of 1st grade of domestic building energy efficiency rating and minimum requirements of ASHRAE 90.1 2004 were no. 16(Takenaka Corporation Tokyo Main office). Buildings that showed annual energy consumption of 300~350kWh/m².a was no. 17(Obayashi Technical Research Institute Main Building), no. 18(Herman Miller Market Place), and no.19(Marunouchi Park Building). Buildings that used yearly energy higher than 350kWh/m².a was no. 20(Tokyo Gas Kohoku NT Building).

Fig. 3 shows the order from lowest to highest regarding annual energy consumption of total 20 high-performance buildings in United States, Japan and Germany. 3 types of horizontal dot lines signify standard value of annual energy consumption. First, average value (293.3kWh/m².a) of CBECS(Commercial Buildings Energy Consumption Survey) database, second, 1st grade of Korea building energy efficiency rating system(more than 200kWh/m².a below 260kWh/m².a), third, energy goal of office building that satisfies minimum requirements of ASHRAE 90.1 2004 (146.6kWh/m².a) were set as standard values.

The range of annual energy consumption of total 20 high-performance buildings is 48~440kWh/m².a, with average value of 169.6kWh/m².a. Compared to average value of CBECS database, except 3 Japan Buildings (no. 17, 19, 20), and 1 United Sates building(no. 18), all of them was shown to have used energy below standard value of CBECS. No. 1~15 received the grade higher than 1st grade and No. 16~20 received the grade below of 1st grade in the domestic building energy efficiency rating. Compared to ASHRAE 90.1 2004, No. 1~12 used energy below 146.6kWh/m².a which is the standard value of ASHRAE 90.1 2004.

Table 2.

Foreign high-performance building’s general information, annual purchased energy and saving rate

Fig. 3.

Annual purchased energy of foreign high-performance building

4.1. Classification and analysis of specified technologies

Table 3 shows specified technology applied in each building, total of 20 high-performance buildings in United States, Germany and Japan. Technology applied to foreign high-performance building was largely classified into 4 fields(Envelope Improvement, HVAC System & Control, Renewable Energy, and Indoor Environment Control), and following states the detailed technology applied by each field.

• Envelope Improvement
   High-R Insulation, Double Skin, High-Performance Insulation, Solar Heat Gain Coefficient, Low-E, Shading Device (Overhang/Fin), Blind
• HVAC System & Control
   High Efficiency Fan & Pump, Displacement Ventilation, Under Floor Air Distribution(UFAD), Chilled Beam, Radiant Cooling, High Efficiency Heating, Cooling Source Equipment, Heat Pump, Building Energy Management System
• Renewable Energy
   Photovoltaic & Solar Thermal, Geothermy/Wind turbine
• Indoor Environment Control
   High Efficiency/Task Ambient Lighting, Daylighting, Dimming Control, Natural Ventilation, Mechanical Ventilation

Fig. 4.

Application rate of high-performance technologies

Fig. 4 shows the graph indicating analyzed technology trend applied in each country of United States, German and Japan.

Envelope Improvement technology is mostly applied in German building (89%) compared to that of United States (35%) and Japan(36%). HVAC System & Control technology was used widely in Japan building(44%). And Renewable Energy technology was used the most in buildings of Japan(75%) showing the similar trend in those of United States(58%), and Germany (63%). Indoor Environment Control technology as well was applied the most in buildings of Japan(65%) and was ranked in the order of United States(52%), and Germany(35%).

Table 3 analyzes application ratio of Envelope Improvement technologies. Buildings in United States showed the relatively high ratio of 75% in Wall High-R Insulation, and application ratio of Envelope Improvement was about 35%. Buildings in Germany showed high application ratio in High-R Insulation, High-Performance Insulation, Solar Heat Gain Coefficient, Low-E, and Shading Device(Overhang/Fin) technologies when compared to those in United States and Japan, and Envelope Improvement application was 89% in Germany, being the highest among those in any country. Japan buildings showed high application ratio of Low-E Glass, and overall application ratio of Envelope Improvement technologies was 36%.

Application ratio in HVAC System & Control showed high ratio of High Efficiency Heating, Cooling Source Equipment in every buildings in United States, Germany and Japan, and the ratios were 83%, 75%, 100% each. Overall ratio of HVAC System & Control was analyzed 26%, 13%, 44% each for United States, Germany and Japan.

Application ratio of Renewable Energy technologies shows that the most applied one is Photovoltaic & Solar Thermal technology with 75%, and 42% in Geothermy/Wind turbine technology in United States Building. In U.S.A application ratio of Renewable Energy technologies was about 58%. German Building's Renewable Energy technologies shows all application of Photovoltaic & Solar Thermal technology with overall application ratio of 63%. Regarding buildings in Japan the application ratio of Renewable Energy technologies was analyzed to be 75% each in Photovoltaic & Solar Thermal technology and Geothermy/Wind turbine technology.

Analysis of Indoor Environment Control shows 92% application in Daylighting technology and 50% application in Dimming Control technology regarding United States buildings. Overall application ratio of Indoor Environment Control technologies was about 52% in U.S.A. In case of German buildings, Mechanical Ventilation was all applied, and the ratio of Indoor Environment Control technology was about 35%. Japan buildings were mainly applied with High Efficiency/Task Ambient Lighting and Daylighting technology, and overall application ratio of Indoor Environment Control technologies was about 65%.

Fig. 5 analyzed application ratio of foreign high-performance building. Based on 4 classifications of high-performance building, the order of average ratio is Renewable Energy(63%), Indoor Environment Control(51%), Envelope Improvement(44%), and HVAC System & Control(28%). In each details of 4 classifications, the technologies mainly applied in high-performance building were high-performance Insulation (70%) of window in case of Envelope Improvement, High Efficiency Heating, Cooling Source Equipment(85%) in case of HVAC System & Control, Photovoltaic & Solar Thermal(80%) in case of Renewable Energy, and Daylighting(80%) in case of Indoor Environment Control.

Table 3.

Specified technologies in foreign high-performance buildings

Fig. 5.

Application analysis of foreign high-performance buildings technologies